Table of Contents
Compiling for UNIX-like platforms (e.g. GNU/Linux, Mac OS X) assumes that the standard GNU toolchain is available. In particular, while compilers other than GCC can be used, the compilation scripts require GNU/make.
To compile the library, it is usually sufficient to change to
VLFeat root directory, denoted
VLFEATROOT in the
following, and type
$ cd VLFEATROOT $ make
The make script attempts to automatically detect the host architecture and configure itself accordingly. If the architecture is not detected correctly, it can be specified manually. For instance
$ make ARCH=glnx86
compiles for GNU/Linux 32-bit.
make help can be used
to obtain a list of other useful options. You can also use
info to obtain a list of the configuration parameters used by
the Makefile, which might allow you do debug any potential issue.
Compiling MATLAB support
In order for MATLAB support to be compiled, the
mex script must be in the current path. If it is
not, its location must be passed to
follows. First, determine MATLAB's root directory by running a MATLAB
session and issuing the
MATLABROOT denote the returned path
script is usually located in
MALTABROOT/bin/mex. Then run
the compilation with the command
$ make MEX=MATLABROOT/bin/mex
VLFeat must be compiled for the architecture used by MATLAB (run
computer command to obtain this information). On
Mac OS X it is often necessary to turn on 64-bit support explicitly by
ARCH=maci64 as both the 32 and 64 bit versions
are plausible targets on 64-bit machines.
Compiling Octave support
Octave support is still experimental. Similarly to MATLAB, Octave
requires compiling MEX files. This can be turned on by passing to make
the path to the
$ make MKOCTFILE=/path/to/mkoctfile
Mac OS X troubleshooting
OS X 10.9 Mavericks, Xcode 5, clang, and GCC
Recent changes to Mac OS X toolkit that ships with Xcode have made compilation of VLFeat slightly more complex. Out of the box, Xcode 5.0 on Mac OS X Mavericks, for example, incorporates the clang compiler but not the GCC compiler. While VLFeat has been updated to use clang in this case, it is worth noting that this compiler does not yet support the OpenMP standard, meaning that multi-core computations would be disabled in this case.
Compiling OpenMP can be achieved by using the GCC compiler, for
example obtaining it from MacPorts. However, anything more recent that
GCC 4.2 will use the MacPorts runtime (C and C++). Since MATLAB links
to the OS X native C and C++ runtime, this breaks the compatibility of
VLFeat MEX files with MATLAB. In particular, while VLFeat does not use
C++, MEX files do as the MEX API is coded in C++ internally (in
particular MEX files are coded with the
option as MEX API calls can throw exceptions, even though they look
like regular C functions). In short, mixing C++ runtimes will cause
MATLAB MEX files to crash every time an error is generated.
The easiest solution at present is to use
gcc-apple-4.2 from MacPorts. Unfortunately, this
version does not support AVX instructions, but supports OpenMP and
creates binaries that are MATLAB compatible.
# Compile VLFeat in a manner compatible with MATLAB and OpenMP support $ sudo port install apple-gcc42 # Install MacPort's distribution of apple-gcc-42 $ make CC=/opt/local/bin/gcc-apple-42 # compile VLFeat using MacPort's GCC
OS X 10.6 Snow Leopard, 64-bit, and MATLAB 2009b.
MATLAB 2009b for Snow Leopard has added 64 bit mex support and a
mexmaci64. VLFeat now supports
compiling for this platform, but the architecture must be specified
manually when compiling, either like:
$ make ARCH=maci64
$ make ARCH=maci
Unfortunately, MATLAB 2009b's
mex script has a bug
that must be manually fixed in order for this procedure to work
correctly. It is recommend to make backup of the
script before attempting this. Th fix the bug, edit the
MATLABROOT/bin/mex script by cutting the line:
get_arch # Call $MATLAB/bin/util/arch.sh
and pasting it after the processing of options:
... shift done #PASTE get_arch call here get_arch # Call $MATLAB/bin/util/arch.sh if [ $v7_compat -eq 1 ] ; then fc_flags="$fc_flags -DMX_COMPAT_32" ...